• 한국안광학회지
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• 제16권1호
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• pp.7-11
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• 2011

목적: 본 연구는 안경렌즈의 색상이 동체 시력에 미치는 변화를 측정함으로써 앞으로 동체 시력 연구에 기초 자료를 얻고자 하였다. 방법: 30명의 대학생을 대상으로 투명한 색, 노란색, 파랑색, 녹색, 갈색의 5가지 색상 렌즈를 착용하고 동체 시력을 측정하였다. 결과: 나안과 콘택트렌즈 착용자 모두 동체 시력은 노란색 렌즈를 착용시 가장 높게 측정되었고, 갈색에서 가장 낮게 측정되었다. 결론: 렌즈 색상에 의해 동체 시력을 향상시키거나 저하시킬 수 있으므로 운동선수 및 높은 동체 시력을 요하는 경우 렌즈 색상의 선택에 있어 신중을 기해야 할 것으로 사료된다.

• Agricultural and Biosystems Engineering
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• 제3권1호
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• pp.35-43
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• 2002

The spectral color resolution of an image is very important in color image analysis. Two factors influencing the spectral color resolution of an image are illumination intensity and lens aperture for a selected vision system. An optimal combination of illumination intensity and lens aperture for color image analysis was determined in the study. The method was based on a model of dynamic range defined as the absolute difference between digital values of selected foreground and background color in the image. The role of illumination intensity in machine vision was also described and a computer program for simulating the optimal combination of two factors was implemented for verifying the related algorithm. It was possible to estimate the non-saturating range of the illumination intensity (input voltage in the study) and the lens aperture by using a model of dynamic range. The method provided an optimal combination of the illumination intensity and the lens aperture, maximizing the color resolution between colors of interest in color analysis, and the estimated color resolution at the combination for a given vision system configuration.

• 한국소음진동공학회논문집
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• 제18권2호
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• pp.192-198
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• 2008

A dynamic analysis of a tilting actuator for a projection TV is presented in this study. Severe vibration of a tilting actuator deteriorates the video quality of a projection TV. For this reason, a dynamic analysis of the tilting actuator system is essential to improve the video quality. The dynamic behaviors of the mirror reactive-type tilting actuator are examined in order to obtain design requirements of the lens transmissive-type tilting actuator. Based on these design requirements, a basic design is performed for the lens transmissive-type tilting actuator. With the basic design, the dynamic characteristics of the lens transmissive-type actuator are investigated by the finite element analysis After the prototype of the actuator is manufactured, the dynamic behaviors of the prototype are examined by experiments. As a result of this study, a new design for the hinge configuration of the actuator is suggested for better performance.

• Design & Manufacturing
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• 제1권1호
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• pp.51-56
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• 2007

As various manufacturing technology of optical glass is developed, the aspheric lenses are supplied to many fields. Electronic or measuring instruments equipped with aspheric lens have recently been used since aspheric lens is more effective than spheric one. However, it is still difficult manufacture glass lens because of high cost and the short life of core. The demands of the aspheric glass lenses increase since it is difficult to obtain the desirable performance in the plastic lens. For the mass production of aspheric lens, specific molds with precisely machined cores should be prepared. In order to obtain competitiveness in the field of industrial manufacturing, a reduction in the development period for the batch machining of products is required. It is essential to analyze the stress distribution and deformations of machining system which is used for manufacturing the aspheric lens using FEM software ANSYS. Finite element simulations have been performed in order to study the influence of machining system which is developed in this study on structures. It is very important to understand the structural behavior of machining system. This paper investigated the static analysis and dynamic analysis of machining system for aspheric lens to predict the damage due to loading.

• Journal of the Optical Society of Korea
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• 제19권1호
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• pp.88-94
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• 2015

This paper reports the fabrication of a lenticular liquid crystal (LC) lens array with thermally tunable focus and with the function of a convertible lens type, using the surface structure of a UV-curable polymer and a twisted-nematic (TN) LC cell. The TN LC cell makes the LC lenticular lens function as a converging or diverging lens by controlling electrically the polarization of input light. Therefore, the focal lengths for both the converging and diverging lenses, which can be switched from the TN cell, can be tuned by changing the effective refractive index of the LC by Joule heating of the transparent electrode. As a result, the focal length of the lens with the E7 LC was changed continuously from 8.7 to 31.2 mm for the converging lens type and from -9.8 to -14.2 mm for the diverging lens when the temperature was increased from 25 to $56^{\circ}C$.

• 전자공학회논문지A
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• 제30A권2호
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• pp.22-28
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• 1993

In this paper, the ultrasonic transducer with a spherical liquid lens is designed and an efficient method to calculate the acoustic field radiated from the transducer is presented. A prototype ultrasonic transducer with a spherical liquid lens is constructed and tested. The experimental results are compared with those of the computer simulations and good agreements are achieved. The dynamic control of the geometric focus is obtained by adjusting the radius of curvature of the lens membrane with the volumetric control of the liquid in the lens.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.140-149
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• 2016

For visual measurement under dynamic scenarios, a zoom lens camera is more flexible than a fixed one. However, the challenges of distortion prediction within the whole focal range limit the widespread application of zoom lens cameras greatly. Thus, a novel sequential distortion correction method for a zoom lens camera is proposed in this study. In this paper, a distortion assessment method without coupling effect is depicted by an elaborated chessboard pattern. Then, the appropriate distortion correction model for a zoom lens camera is derived from the comparisons of some existing models and methods. To gain a rectified image at any zoom settings, a global distortion correction modeling method is developed with bundle adjustment. Based on some selected zoom settings, the optimized quadratic functions of distortion parameters are obtained from the global perspective. Using the proposed method, we can rectify all images from the calibrated zoom lens camera. Experimental results of different zoom lens cameras validate the feasibility and effectiveness of the proposed method.

• Journal of the Optical Society of Korea
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• 제16권1호
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• pp.22-28
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• 2012

We report a focal-length tunable liquid lens based on thermopneumatically driven fluidic pressure. The fluidic pressure is generated by deformation of an elastomeric diaphragm induced by thermopneumaticity from a laterally integrated microheater sealed within an air chamber. The pressure is transmitted by a confined liquid to a lens diaphragm through an internal fluid channel. The liquid filling under the lens diaphragm functions as a liquid lens for dynamic focusing with properties depending on the curvature of the deformed diaphragm. The diaphragm area of the air chamber is designed five times larger than that of the lens cavity to yield high focal-length tunability by amplified deflection of the lens diaphragm. With our method, we achieved excellent focal-length tunability from infinity (without an input current) to 4 mm (with an input current of 12 mA) with a lens aperture diameter of 2 mm.

• 한국광학회지
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• 제15권2호
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• pp.130-136
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• 2004

3차원 완전 결상에서 동적 배열 렌즈 방식을 사용하여 해상도를 향상시킬 때, 해상도 향상 특성을 조사하였다. 렌즈 배열의 이동 방향 및 이동 거리에 따라 관측 해상도가 달라짐을 컴퓨터 합성 완전 결상을 이용하여 보였다. 이를 통해 효율적으로 관측 해상도를 향상시킬 수 있는 렌즈 배열의 이동 조건을 찾을 수 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.207-212
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• 2006

A dynamic analysis of a tilting actuator for projection TV is presented in this study. Generally, an excessive vibration of a tilting actuator is occurred a lowering of video quality of projection TV because of a dynamic unstability of it. Therefore, a dynamic analysis of a tilting actuator system is positively necessary. In this study, a mathematical model about a mirror-reactive type tilting actuator is presented and evidenced by experiment. A FEM model of a lens-transmissive type tilting actuator is presented and we made prototype of it. Then, it is evidenced by experiment. Besides, a design for hinge configuration of it is presented.